A liquid crystal panel included in a liquid crystal display device such as a liquid crystal television does not emit light, and thus a backlight device is required as a separate lighting device. A backlight device is generally arranged behind the liquid crystal panel (i.e., on a side opposite from a display surface side). It includes a chassis, alight source, a reflection sheet, and an optical member (a diffuser). The chassis has an opening on the liquid crystal panel side. The light source is housed in the chassis. The reflection sheet is arranged along the inner surface of the chassis and configured to reflect light toward the opening of the chassis. The optical member is arranged over the opening of the chassis and configured to efficiently release light emitted by the light source to the liquid crystal panel side. The light source, which is one of the components of the above backlight device, may be LEDs. When the LEDs are used, an LED board on which the LEDs are mounted may be housed in the chassis.
A backlight device using LEDs as a light source is disclosed in Patent Document 1.